Photoelectrically controlled protection means for loom



Oct. 16, 1956 A. LARAIA ETAL 2,756,781

PHOTOELECTRICALLY CONTROLLED PROTECTION MEANS FOR LOOM Filed May 23.1951 2 Shets-Sheet 1 FEGJ INVENTORS ARTEMIO LARAIA VICTOR F. SEPAVICHATTORNEY Oct. 16, 1956 A. LARAIA ETAL 2,766,781

PHOTOELECTRICALLY CONTROLLED PROTECTION MEANS FOR LOOM Filed May 23.195] 2 Sheets-Sheet 2 INVENTORS ARTEMIO LARAIA VICTOR F.SEPAVIGHATTORNEY.

United States Patent M PHOTOELECTRICALLY CONTROLLED PROTEC- TION lVIEANSFOR LOOM Artemio Laraia and Victor F. Sepavich, Worcester, Mass.,assignors to Crompton & Knowles Loom Works, Worcester, Mass., acorporation of Massachusetts Application May '23, 1951, Serial No.227,844

7 Claims. (Cl. 139-341) This invention relates to improvements inprotection means for looms and it is the general object of the inven-'tion to control loom operation by a photoelectric cell the illuminationof which at a critical time in the loom cycle is determined by theposition of the shuttle along its path of flight, the loom beingpermitted to continue in operation if the shuttle is running on time butbeing stopped if the shuttle is running late.

The usual protection in fly shuttle looms includes a protector rodhaving one or more daggers and fingers for engagement with the shuttlebinders in the shuttle boxes. The daggers are ordinarily in stoppingposition but timely arrival of the shuttle at a shuttle box acts throughthe protector fingers to move the daggers away from stopping position topermit continued loom operation. Such mechanisms require that theshuttle actually reach the shuttle box before an indication forcontinued loom operation can be given, but in fast running looms thisindication comes so late in the cycle of the loom that if stoppage isnecessary to prevent the shuttle from being pushed into the warp threadsby the reed the stopping action must be very abrupt and is likely tocause damage to some part of the loom.

It is an important object of the present invention to be able todetermine in advance of actual arrival of the shutshuttle at the shuttlebox whether or not it is running on time and to effect thisdetermination by causing the shuttle if running properly to effect achange in the illumination of a photoelectric cell at a given time inthe loom cycle. If the shuttle is running late it will not be able toeffect this change at the given time and electrically controlled meanswill then initiate loom stoppage earlier in theflight of the shuttlethan is possible with the ordinary protection mechanism.

It is a further object of the invention to direct a beam of lightthrough the top and bottom sheets of warp threads which form the warpshed of the loom toward the shuttle path and rely upon shuttle presencein the warp shed at the beam of light to alter the amount of lightfalling on the photoelectric cell for the purpose of effecting continuedloom operation. It is found that although the warp threads cast someshadow it is not sufficient to interfere with adequate illumination ofthe photoelectric cell. This condition is believed to be due partly atleast to the fact that some of the warp threads will be in the top sheetand the remainder in the bottom sheet so that the beam of light at thecritical time in the loom cycle when indication of shuttle presence isgiven is not required to pass through a single sheet of warp threadssuch as might cast sufiicient shadow to interferewith correct operation.

The aforesaid change in illumination may be either a decrease or anincrease in the amount of light falling on the photoelectric cell. Whendecreased illumination is utilized the shuttle will cast a shadow on thephotoelectric cell, and when increased illumination is utilized areflector on the shuttle will deflect a beam of light toward thephotoelectric cell.

The ordinary shuttle used in fly shuttle looms will have solid ends oneof which will carry a shuttle eye and the other of which may carry abobbin clip to hold a bobbin extending between the ends of the shuttle.The bobbin is ordinarily centrally located transversely of the shuttleand it is a further object of the invention when utilizing decreasedillumination of the photoelectric cell to locate the beam of light sothat it will be interrupted not only by the solid ends of the shuttlebut also by the bolgbin even though-the latter is substantially depletedof we t.

When reliance is placed on a decrease of light falling on the cell toeffect continued loom operation the filament of the source of light mayburn out or otherwise fail, in which event a condition will eXistequivalent to the casting of a shadow on the photoelectric cell andunder these conditions the loom would be without protection. In order toguard against this contingency it is a further object of the inventionto employ a control circuit which is dependent for its closure uponcontinued flow of current through the lamp, and if the filament of thelatter should break the circuit will be open and cause prompt loomstoppage.

When increased illumination is relied upon to eifect continuedloomrunning the photoelectric cell will be out of the normal path of thebeam of light and the shuttle will be provided with a reflecting surfacewhich crosses the beam of light and deflects it toward the cell.

Whether decreased or increased illumination of the cell is utilized theshuttle must be present at the beam of light to cause the aforesaidchange in the amount of light falling on the cell.

In order that the invention may be clearly understood reference is madeto the accompanying drawings which illustrate by way of example twoembodiments of the invention and in which:

Fig. l is a front elevation of the loom, parts being broken away, havingapplied thereto the preferred form of the invention'which relies upondecreased illumination of the photoelectric cell,

Fig. 2 is an enlarged vertical section on line 2-2, Fig. 1, showing thelay in full lines in the position which it occupies while the shuttle isin flight through the warp shed and in broken lines when the lay is atfront center,

Fig. 3 is an enlarged detailed end elevation looking in the direction ofarrow 3, Fig. 1,

Fig. 4 is a plan view of the shuttle and bobbin therein such as may beused with the'invention,

Fig. 5 is a diagrammatic view of a form of electric circuit which can beutilized to carry the preferred form of the invention into effect,

Fig. 6 is a view similar to Fig. 2 but showing the modified form of theinvention which relies upon increased illumination of the photoelectriccell,

Fig. 7 is an enlarged detail front elevation of part of the loom lookingin the direction of arrow 7, Fig. 6,

Fig. 8 is a diagrammatic view similar to Fig. 5 but showing the electriccircuits for the modified form of the invention, and

Fig. 9 is an enlarged horizontal section on line 9-9, Fig. 2, showingspaces forward of the reed dents and between groups of warp threadsbetween the dents.

Referring to Fig. 1, the loom has right and left loomsides 1 and 2,respectively, which support a rocker shaft 3 for the right and leftlay'swords 4 and 5, respectively, which support the lay designatedgenerally at 6. In the present instance the lay has a single shuttle boxR at the right end thereof and a gang L of two shuttle box cells 7 and 8at the left end thereof. The loom in the present instance operates withtwo means to lay weft in a warp shed, shown herein as shuttles one ofwhich Si is shown in the loom shuttle'box R and the other of which 3 S2is shown at the left end of the loom in tle box cell 8.

The lay swings backwardly and forwardly in the loom is usual manner bypower imparted to its from a top shaft iii through connectors one ofwhich is shown at 11 in Pig. 2. The top shaft has a gear 12 securedthereto meshing with a gear 13 of twice its size secured to the bottomshaft 14. The latter shaft has right and left picking arms 15 and 16 forcooperation with picking earns 17 and 18, respectively operativelyconnected to picker sticks P1 and P2, respectively. The picker sticksoperate one at a time and usually during the backward stroke of the layat a time when the latter is at or near its top center position, thatis, approximately midway between its extreme front and back positions.Each picker stick when operating will propel the shuttle aligned with itfrom one end of the loom to the other end, causing it to pass through awarp shed designated generally at W, see Fig. 2, comprising upper andlower sheets, planes or groups of weft work threads 20 and 21,respectively. These threads pass through a reed 22 the lower edge ofwhich is positioned by the lay beam member 23 and the upper edge ofwhich is positioned by a hand rail member 24. The latter is supported byarms 25 one of which is shown in Fig. 2 extending upwardly from the laystructure 6. The lay beam has a shuttle race 26 under the hand rail andalong which theshuttles travel when in flight between shuttle boxstructures R and L.

At the time of picking of a shuttle the lay will be moving rearwardly,or to the right as viewed in Fig. 2, and will ordinarily reach its backcenter position while the shuttle is in flight and in the warp shed. Thelay will then start forwardly as the shuttle continues to move throughthe shed. If for any reason the shuttle should be traveling slower thanusual, or should be stopped in the warp shed, it is necessary to effectprompt stoppage of the loom in order to prevent the reed 22 from pushingthe shuttle forwardly through the warp shed and breaking some of thewarp threads. It is the general purpose of the present invention toeffect this stoppage of the loom should the shuttle fail to reach agiven point in its travel along the lay at a given time in the cycle ofthe loom.

The invention to be set forth hereinafter may operate on a bobbinchanging loom having a reserve bobbin magazine M to effect replenishmentof each of the two shuttles when they are substantially depleted ofweft. The shuttles may both be as shown in Fig. 4, wherein shuttle S1 isparticularly set forth. The shuttle has ends 30 and 31 as shown at theright and left, respectively, of Fig. 4 and these ends will be soconstructed as to be opaque to the passage of light. The end 30 may beprovided with a shuttle eye 32 while the end 31 may be equipped with aspring jaw 33 to hold the head 34 of a bobbin designated generally at B.The bobbin will include a barrel 35 exthe lower shuttending to the rightfrom the head 34 as viewed in Fig. 4

and terminating in a tip 36 which will ordinarily be closely adjacent tobut spaced from the end 30 of the shuttle. The barrel 35 of the shuttlehas a mass of weft 37 wound thereon which will become depleted duringloom operation so as to uncover the greater part of the barrel 35. Thespring jaws 33 will ordinarily hold the bobbin B so that its barrel islocated substantially centrally transversely of the shuttle, as isapparent from Fig. 4.

Both of the shuttles S1 and S2 may be as set forth in Fig. 4 althoughthe invention is not necessarily limited to use with shuttles adaptedfor weft replenishment, but when such shuttles are used the bobbinbarrel 35 can be relied upon to effect part at least of the decreasedillumination already mentioned hereinbefore. It will be understood thatthe shuttle will be formed with a bobbin compartment 38 which is open atits bottom to permit expulsion of a depleted bobbin as a fresh bobbin isinserted into the shuttle from above.

The matter thus far described may be constructed and operated in theusual manner.

The loom is driven by a motor 40 which as shown herein is provided witha pinion 41 meshing with a motor gear 42 fixed to the top shaft 10. Themotor is of the socalled stop and start type and whenever the motor isin operation the loom will be running and whenever the motor is stoppedthe loom will stop with it. The motor is controlled by electricaldevices which need not be described in detail herein but which arecontained in'a panel or box 43, see Fig. 5, which in turn are controlledby a master relay 44. The relay controls a master switch MS, see Fig. 5,having an armature or which blade 45 and a contact 46 therefor. When therelay 44 is energized the blade 45 is in engagement with the contact 46and wires 47 and 48 leading from the switch MS to the panel 43 areelectrically connected and maintain the condition for continued runningof the motor. If the relay 44 becomes deenergized the spring 49 willopen switch MS and the wires 47 and 48 will be electricallydisconnected, whereupon the equipment within the panel 43 will effectvery prompt stoppage of the motor and loom. The master relay 44 and itsswitch, and the equipment controlled by the switch may be considered tobe loom governing means controlling motor and loom operation capable ofeither stopping the loom or continuing its operation.

Loom stoppage may be effected by any of the known electrically operatingmeans for this purpose, such as by a magnetic brake, or by applicationof a so-called plugging current which will stop the motor almostinstantly. The motor 40 will ordinarily be operated by a threephasealternating current and the plugging may be effected by direct current.We do not wish to be limited to any particular means for stopping themotor and it will be sufiicient for the purposes of the invention ifelectric means operates to stop the motor upon deenergization of themaster relay 44.

The invention operates with two switches one of which is a loomcontrolled timer switch designated at T5 and the other of which is ashuttle controlled switch designated at SS. The timer switch includes acontact arm 50 normally held against contact 51 by a spring 52 but movedaway from the contact 51 periodically by a cam 53 having a cam point 54.The cam 53 is secured to a shaft 55 mounted for rotation in a stationarystand 56 which may be mounted on the left hand loomside 2 as viewed inFig. 1. The stand 56 supports the arm 50 and also the contact 51. Asprocket wheel 58 secured to the top shaft 10 is connected by a chain 59to another sprocket wheel 60 of the same size as sprocket 58 secured tothe shaft 55. The cam 53 therefore completes a rotation each pick orbeat of the loom and the cam point 54 will open the timer switch TS atregularly recurring intervals each pick of the loom when the shuttleshould be at a given point in the path of its travel along the lay. Wedo not wish to be limited to the particular type of timer switch shownin Fig. 3, and it will be sufiicient if the timer switch is normallyclosed but opens periodically.

The master relay 44 is in a circuit including a transformer 65, wire 66,relay 44, wire 67, contact 51, arm 50, wire 68, switch LS to bedescribed more in detail hereinafter, and wire 69 back to thetransformer. The contact 51, arm 5t and part of wire 68 may beconsidered as one of two parallel branch circuits the other of whichwill be described hereinafter. During the greater part of the cycle ofthe loom this branch circuit will be closed and the master relay will bemaintained energized by current flowing through the switch TS, but asalready mentioned this circuit will be opened periodically and unlessrelay 44 is energized by closure of the switch SS it will becomedeenergized and effect loom stoppage.

In the preferred form of the invention the loom is provided with meansfor directing a beam 70 of light across the path of the shuttle andpreferably through. the warp shed. As shown in Figs. 1 and 2, this beamof light may be provided by an illuminating element, such as an electriclamp 75, carried by a small stand 76 secured at 77 to the hand rail. Thehand rail has a hole 78 therethrough below the lamp and whenever thelatter is illuminated its filament 79 will direct a beam of light down.through the hole 78 from one side of the warp shed, the upper side asshown herein.

The lay beam 23 is provided with a hole 80 aligned with the hole 78, anda photoelectric cell unit or element 81 is secured to the under side ofthe lay beam on the other side of the warp shed, said other side asshown herein being the under side of the shed. The photoelectric cell,designated more particularly at 82 as part of unit 81, will be in thepath of a beam of light originating with the filament 79 and passingdownwardly through the hole 78, through the upper and lower sheets 20and 21 of warp threads, across the shuttle race 26, and through the hole80 in the lay. This beam of light crosses the shuttle path and will beintercepted by a shuttle passing along the lay. When the type of shuttlealready decribed is used the beamof light will be spaced forwardly fromthe reed 22 a distance approximately equal to the distance from thetransverse center of bobbin barrel 35 to the reed, see Fig. 2, when theshuttle is against the reed.

Two wires 85 and 86 supplying preferably direct current are connected byresistances R1, R2 and R3 which are in series as shown in Fig. 5.Adjustable tap 87 is slidable along the resistance R2 and is connectedto a resistance R4 which in turn is connected to a junction point 88. Anelectronic tube E preferably of the high vacuum type has a cathode 90, acontrol grid 91, and a plate 92. The plate 92 is connected by wire 93 toa control relay 94 which controls the switch SS. The other side of therelay 94 is connected to the positively charged wire 85.

Negatively charged wire 86 is connected by resistance R5 to the cathode90 and also to the cathode or negative element 95 of the photoelectrictube 82 which is also preferably of the vacuum type. The anode orpositive element 96 of the photoelectric cell is connected by wire 97 tothe junction 88.

The resistance R4 and the photoelectric cell 82 jointly control theelectrical potential of the junction 88 and under normal conditions whenthe beam of light from the filament 79 is uninterrupted the voltage ofthe junction 88 will be at such electric level that the grid 91 willpermit suflicient current to flow through the electronic tube E tomaintain the control relay 94 energized and the latter will hold itscontact or switch blade 98 away from a contact 99 as shown in full linesin Fig. 5. Switch blade 98 is connected by wire 100 to the wire 67 andcontact 99 is connected by wire 101 to wire 68. Wire 100, blade 98,contact 99 and wire 101'constitute a second branch circuit in parallelwith the first mentioned branch circuit. The switches TS and SS aretherefore in parallel branch circuits both connected to the master relay44.

The control relay 94 will be energized sufiiciently to maintain theshuttle switch SS open when the shuttle S1 is in the full line positionin Fig. 5, but when the shuttle as it travels through the shed reaches agiven point along its path where its advancing end intercepts orinterrupts the beam of light a shadow will be cast on the photoelectriccell 82 to decrease its illumination and there will be a change in theelectric potential of the junction 88 such as will cause the grid 91 tobecome more negative than it was previously and the amount of currentwhich can flow through the tube E will be insuflicient to maintain thecontrol relay 94 energized. The switch SS will thereupon be closed, seedotted lines in Fig. 5, and if this closure occurs at the time in theloom cycle while switch TS is open due to the fact that the shuttle isrunning on time the master relay 44 will remain energized and the loomwill continue to run. If, however, the shuttle is running late or hasnot been able to intercept the beam of light when switch TS opens thenboth of the aforesaid parallel branches of the electric circuit of themaster relay will be open and the latter will become deenergized withconsequent opening of switch 45 and resultant stoppage of the motor 40and the loom.

In the aforegoing description there has been set forth means forcreating a single beam of light which will be located more or lesscentrally of the length of the lay, as will be apparent from Fig. 1. If,however, it should be desired to have the shuttle give indication of itspresence when nearer the shuttle box toward which it is traveling twobeams of light can then be used and the cam which operates the timerswitch will be set to ope nswitch TS a little later in the loom cycle ina manner as set forth for instance in Patent No. 2,586,335, issuedFebruary 19, 1952 to the present inventor Sepavich and Howe.Interception of the beam of light will ordinarily occur while the lay isin a position substantially behind the position which it ordinarilyoccupies with the usual protector rod type of protection, and thereforemore time will be allowed for stopping the loom before there is dangerthat a shuttle trapped in the shed will be pushed through the warpthreads.

If the lamp should fail, as by burning out of the filament 79, no beamof light would fall on the photoelectric cell and the latter would be ina condition of decreased illumination and keep switch SS closed Withoutregard to the position of the shuttle, and the loom would be withoutprotection. In order to guard against this contingency the previouslymentioned switch LS will be under control of the lamp circuit. Thisswitch LS has a contact 105 normally engaging an armature blade 106because of continued energization of an electromagnet 107. The latter isin series with the lamp which derives its power from a transformer 108as will be apparent from Fig. 5. Whenever the filament '79 burns outcurrent will be interrupted in the electromagnet 107 and the spring 109will then open the switch LS which, being in series with transformer 65,will immediately efiect deenergization of the master relay 44. Theelectromagnet 107 is shown herein as a convenient means for keeping theswitch LS normally closed, but we do not wish to be limited to the useof such a magnet, and any form of control for switch LS may be usedwhich will keep the switch closed when the filament 79 is intact butwill effect opening of switch LS upon failure of the filament.

In operation it is found that the warp threads will not ordinarily casta sufiicient shadow on the photoelectric cell to preventillumination ofit at a level sufficient to maintain the:control relay 94 energized. Thepassage ofthe shuttle through the beam of light, except where very densewarps are used, will always effect a sufiicient change in theillumination of the photoelectric cell. to cause the desired change inthe grid 91. It will be understood that when the lay reaches theposition shown in broken lines in Fig. 2 the fabric F will be in thepath of the beam of light and may momentarily cast a shadow on thephotoelectric cell, but this occurs at a time in the loom cycle afterswitch TS has closed, and these is no likelihood that the shadow cast bythe fabric can interfere with the operations already described.

In the modified form of the invention, an example of which isillustrated in Figs. 6 to 8, the photoelectric cell depends upon anincrease in its illumination by the shuttle at the aforesaid given timeto permit continued running of the loom. In this form of the inventionmuch of the matter thus far described will be used, but instead of theshuttle casting a shadow on the photoelectric cell the shuttle is somade that it will reflect a beam of light onto the photoelectric cell toincrease the amount of light falling on it.

Fig. 6 shows a lay beam 115, a hand rail 116, and a reed 117 along whicha shuttle S3 travels when laying weft in the warp shed W. The hand railhas mounted thereon a source of illumination or lamp element 120 whichmay be held in position with respect to the hand rail by a bracket 121secured to the hand rail at 122.

7. Hand rails customarily employ some form of shuttle. guard which isindicated. herein at 123 and this: guard may be utilized to assistinsupportingxthe, bracket 111 as shown in Fig. 6, or may if desired bethe sole support for the lamp element.

The shuttle S3 has the front wall. thereof provided with a reflector 125on which light from thelamp element 120 can fall. Secured to the forwardpart of the lay beam 115 is a photoelectric cell unit 126 held in.position on the lay by a bracket 127. The bracket is provided with ahood 128 which opens upwardly and rearwardly toward the shuttle path andprevents direct illumination of the cell element by the lamp element.

As is apparent from Fig. 7 the lamp element and photoelectric cellelement are arranged one above the other and preferably in such relationthat the beam of light, shown at 130, will travel downwardly andrearwardly through the top sheet 20 betweenv the threads thereof againstthe reflector 125 and from the latter downwardly and forwardly throughthe bottom warp. sheet 21. The arrangement set forth more particularlyin Fig. 6- is set forth as an example and we do not wish necessarily tobe limited to the particular location of the reflector on a shuttle orthe disposition of the lamp and photoelectric cell elements. It will besuificient for the purposes of the modified form of the invention itpassage of the shuttle is the means by which light originating with thelamp element can be caused to illuminate the photoelectric cell element.

Under normal conditions the lamp, which may be similar to the lampdescribed in connection with the preferred form of the invention,directs a. beam of light through the top warp sheet 20 and when theshuttle in its passage along the lay enters the beam of light thereflector 125 will deflect the beam of light downwardly and forwardlythrough the hood or shield 128 on to the cell 126. If the shuttle is ontime in its flight it will reflect the beam of light to increase theillumination of. the photoelectric cell at the correct time in the cycleof the loom, but if the shuttle is late, or for any other reason failsto enter the beam of light at the correct time, the illumination of thephotoelectric cell will not be increased and the loom will be stopped Alarge part of the electric circuits usedwith the modified form of theinvention will be similar to that already described for the preferredfrom of the invention, but when a photoelectric cell actsdue to'increase in its illumination it is necessary to make some changes in itselectric connections, as indicated in Fig. 8 which is similar to Fig.except for these changes and the control for the switch of the branchcircuit which is controlled by the photoelectric cell.

In the modified form of the invention the photoelectric cell 126 has itsanode 131 connected by wire 132 to the previously described positivelycharged wire 85, and its cathode 133 connected by wire 134- to junction88. A relay 135 corresponding to previously described relay 94electromagnetically controls a switch blade 135 which is normally spacedfrom a contact 137 throughout the greater part of the loom cycle.Whenever relay 135 is energized it attracts the armature balde 136- andmoves it against contact 137, and upon deenergization of the relay 135 aspring 138 returns the blade 136 to its normal noncontacting position.

In the operation of the modified form the photoelectric cell 126 willnot be illuminated except briefly at periodic intervals, and because ofthis fact the junction 88 is normally at a relatively low potential andmaintains the grid 91 in such electric condition that insufficientcurrent can flow through the electronic tube to energize relay 135. Whenthe shuttle reflects the beam of light 13!) toward the cell 126 thelatter is able to conduct more current and has the efiect of raising thepotential of the junction 88, whereupon the grid 91 is made lessnegative and enough current can. pass through the: electronic tube to.energize the relay and. cause the latter to effect engagement betweenthe. blade 136 and contact 137..

and the master relay will remain energized; I-f,.however, the.energi'zation of. the relay 135. does not occur, due to a lateorslowrunning shuttle, until after the timer switch is open, the masterrelay will then become deenergized. and. the loom will he stopped asalready described.

No matter how dense thev warp may be with regard to either its opacityor number of threads to the inch each reed. dent will separate thethreads of both the top and bottom warp sheets at: the sides of it intogroups between which there. will be a. space in front of the dent, andthe source of light: and. photoelectric cell can be so located that the.beam of light can register with and be directed through one or moreofthe. spaces forward of the reed dents. Thus, in Fig. 9 separate den-tsof reed. 22. are designated at 140 and. the spaces between groups 141 ofwrap. threads are shown at 142. These spaces are triangular shaped. andextend forwardly from the dents to the fabric F. If the beam of light70, for instance, is aligned with a. space 1422 as shown in Fig. 9enough light will get through both sheets of the warp for properillumination of the photoelectric cell. The beam of light may in fact bewide enough to. pass through two or more of the spaces 1142 if the reedis of fine gauge.

From the foregoing; it will be seen that the invention sets forth simplemeansaby which operation of a loom is controlled byelectric meansincluding a photoelectric cell which due to a change in its illuminationwill permit the loom to continue running it the change occurs at a giventime in the loom cycle. The change in illumination of the cell iseitectedby the shuttle, and this change may be a decrease in the:illumination of the cell if the preferred form of the invention is usedwherein the shuttle casts a shadow, or the change may be due to anincrease in illumination-of the cell it the modified form of theinvention is used wherein the reflector 125 on the shuttle momentarilydeflects light. onto the photoelectric cell.

In both forms of the invention the beam of light will pass through theWarp shed when it is desired that the shuttle give an indicationcomparatively early in its travel. Although a single beam of. light hasbeen shown two beams can be spaced along the length of the lay onopposite sides of the beam shown for instance in Fig. l and the timerswitch can then. be set a little later. In the preferred form of the.invention failure. of the lamp would create the condition of decreasedillumination and in order to prevent continued loom operation underthese conditions the switch LS is provided which is dependent for itsclosure upon flow of current, through the lamp. In the modified form ofthe invention the switch LS is not necessary, since burning out ofrthelamp filament would prevent an increase in the illumination of thephotoelectric cell and the loom would be promptly stopped. In thepreferred form of the invention, particularly when the shuttle can beutilized to interrupt the beam of light. While the lamp has been shownas being supported by the hand rail and the cell by the lay beam, thesetwo elements can or" course be interchanged with respect to the handrail and lay beam members. The invention also sets forth novel .laystructures carrying lamp and photoelectric cell elements, the lay forthe preferred form of the invention having these elements directly inline so that the beam of light passes from one to the other, while thelay for the modified form of the invention has at least one of theelements hooded or shielded so that the cell element cannot be excitedby direct light derived from the lamp element. The switches TS and SSand the photoelectric cells, together with their electric connections,may be considered as control means for the loom governing means, thelatter including the master relay 44 and its connections to thepanel 43.Also, the beam of light can This: engagement. will occur when the timerswitch 'is open if the: shuttle is running on. time.

be in register with one or more of the reed dents to pass through one ormore of the spaces 142 forward of the reed.

Having now particularly described and ascertained the nature of theinvention and in what manner the same is to be performed, what isclaimed is:

1. In protection means for a loom dependent for continued operation uponclosure of electric circuit means and a regularly recurring decrease inthe illumination of a photoelectric cell, electric means including alamp filament to illuminate said photoelectric cell, an electric switchin series in said electric circuit means, and means dependent upon flowof electric current through said filament to effect closure of saidswitch and effective to open said switch upon failure of electriccurrent to flow through said filament.

2. In protection means for a loom having a ward shed and providing apath for a shuttle in flight, a source of light on one side of the shedcausing a beam of light to be directed toward said path, a photoelectriccell on the opposite side of the shed out of said beam of light,electric loom controlling means including the photoelectric celleffective upon an increase in the illumination thereof at a given timein the cycle of the loom to continue loom operation and effective uponfailure of an increase in the illumination at said time to stop loomoperation, and a shuttle effective when reaching a given point in theflight thereof to cooperate with said source to cause an increase in theillumination of said photoelectric cell.

3. In a lay and shuttle for a loom, a light source element on the lay, aphotoelectric cell element on the lay, means on the lay preventingdirect illumination of the cell element by the source element, and ashuttle having a reflector thereon effective when located at a givenpoint along the lay to reflect light from said source element onto saidcell element.

4. In a loom, a light source element, a photoelectric cell element,means preventing direct illumination of the cell element by the sourceelement, a shuttle comprising a reflector effective when the shuttle isin flight to reflect light from the source element onto the cell elementto increase the illumination of said cell element, and means effectiveto stop the loom upon failure of the reflector to effect a change in theillumination of said cell element at a given time in the cycle of theloom.

5. In protection means for a loom having a shuttle which when runningproperly passes a given point in its path at a given time in the loomcycle, means to create a beam of light at said point, a photoelectriccell normally out of the path of said beam of light, a reflector on theshuttle elfective when the shuttle is at said point to reflect said beamof light onto the photoelectric cell to increase the illumination of thelatter, and loom controlling means controlled by the photoelectric celleffective to cause continued loom operation upon an increase ofillumination of said photoelectric cell at said time and effective tostop the loom upon failure of said photoelectric cell to have theillumination thereof increased at said time.

6. In protection means for a loom providing a path for a shuttle inflight, a source of light, a photoelectric cell forward of said path,electric loom controlling means including said photoelectric celleffective upon an increase in the illumination thereof at a given timein the cycle of the loom to continue loom operation and effective uponfailure of an increase in the illumination of the photoelectric cell atsaid time to stop loom operation, and means causing the shuttle whenreaching a given point in the flight thereof to cooperate with saidsource to cause an increase in the illumination of said photoelectriccell.

7. The protection means set forth in claim 6 wherein the source of lightdirects a beam of light to one side of the photoelectric cell and theshuttle when reaching said given point directs the beam of light towardthe cell.

References Cited in the file of this patent UNITED STATES PATENTS2,026,147 Turner Dec. 31, 1935 2,279,675 Gutman Apr. 14, 1942' 2,670,014Hutchison Feb. 23, 1954

